Regular Article

Explanations of the g factors for the tetragonal (MoO₄)³⁻ clusters in γ-irradiated (MoO₄)²⁻-doped KDP and ADP crystals through the dynamic effect

¹ School of Chemistry & Chemical Engineering, Mianyang Normal University, Mianyang 621000, P.R. China
² School of Physics & Electronic Engineering, Mianyang Normal University, Mianyang 621000, P.R. China
³ Research Center of Computational Physics, Mianyang Normal University, Mianyang 621000, P.R. China
⁴ Department of Material Science, Sichuan University, Chengdu 610064, P.R. China

^a e-mail: zhengwc1@163.com

Received: 24 January 2016
Revised: 9 June 2016
Accepted: 5 July 2016
Published online: 26 July 2016

Abstract

The electron paramagnetic resonance (EPR) g factors g_// and g_┴ for the tetragonally-compressed (MoO₄)³⁻ clusters in the γ-irradiated (MoO₄)²⁻-doped KH₂PO₄ (KDP) and NH₄H₂PO₄ (ADP) crystals are computed from the high-order perturbation formulas based on the two (crystal-field and charge transfer)-mechanism model for the compressed d¹ tetragonal tetrahedra with the ground state |d_z²⟩. From the calculated values and by taking account of the mixing of the first-excited state |d_x²−y²⟩ to the ground state |d_z²⟩ caused by the dynamic effect due to the vibration of ligands (which can result in a twinkling change of tetrahedron from compression to elongation), the computed g_// and g_┴ for the two crystals are in good accordance with the experimental values. The large deviations of the observed g_// from g_e (≈2.0023, the g factor of free electron) in both crystals are therefore explained. The results are discussed.